The last few weeks I was on a diet. Not that I am too fat, but for some experiments I need to follow a strict diet, such as for the European SOLO experiment. Twice Dan Burbank and I ate a special diet for five days. The experiment is about salt and is called SOLO (SOdium LOad in microgravity). Dan and I eat a diet with normal salt content for a week (11.5 grams a day), and a diet with low salt the other week (2,9 grams a day). Scientists can work out the influence of salt on our bones based on the results. In space you lose bone mass very quickly. You could say that we ‘age’ very quickly. This aspect of space benefits research on Earth. Many old people suffer from bone decalcification (osteoporosis). This experiment might help people on Earth with this disease. We now know that eating more salt increases the acid content in the human body and this might increase bone loss. ESA’s SOLO experiment will investigate whether eating less salt decreases the effects of bone loss.
That is the theoretical part. In practice up here on the ISS things are a different story. Think about having a very strict diet as well as having to store all your urine in a bag. In space going to the toilet is an expedition in itself, even more so if you have to store each pee. Getting blood is also a challenge in microgravity. I draw Don’s blood and my own blood in ESA’s Columbus module. A tricky process involving needles, tubes and plasters. The samples that we take need to be frozen in the Station’s -80 degree freezers called MELFI that are in the Japanese laboratory Kibo. We also need to weigh ourselves. We use a special spring-loaded device that moves us up and down. By measuring the delay in the spring we can calculate our body mass. The blood and urine samples will travel with the next Soyuz spacecraft to America and Europe via Russia. The ISS is truly an international undertaking.
SOLO is an important experiment for ESA. As many guinea pigs as possible need to take part to achieve valid scientific results. Last year Paolo Nespoli took part in SOLO. All astronauts in future missions will be asked if they wish to participate. Sometimes it can be hard. For example when a new Progress freighter arrives. Right in the front of the cargo are fresh fruit and nice things that our families send up. But I was not allowed to eat any of those of course. I was allowed one ‘free’ day in between the diets. I immediately plundered the stock of oranges…
News from the Netherlands
I follow the news from the Netherlands as much as I can. Prince Johan Friso's hospitalisation has been on my mind recently. I have been twittering and blogging less because of Friso’s situation. My thoughts are with the royal family in these difficult times.